Guard for the rotating portions of air-moving devices



y 1952 c. M. BUTTNER 2,601,947

GUARD FOR THE ROTATING PORTIONS 0F AIR-MOVING DEVICES Filed March 30, 1950 [NVE'N'Z'OR CARL M. BUTT/V51? Patented July 1, 1952 GUARD FOR THE ROTATING PORTIONS AIR-MOVING DEVICES Carl M. Buttner, Memphis, Tenn., assignor .to

Hunter Fan and Ventilating Company, Memphis, Tenn., a corporation of Tennessee Application March 30, 1950, Serial No. 152,779

moving devices. More particularly this invention relates to improvements in guards for the rotating portions of air-moving devices.

It is therefore an object of the present invention to provide an improved guard for the rotating portions of air-moving devices.

The problem of guarding the rotating portions of air-moving devices against contact with the fingers, hands, or other portions of the anatomies of persons adjacent to such air-moving devices is one that has perplexed manufacturers of airmoving devices for man years. A large number of different kinds, sizes and shapes of guards for air-moving devices have been proposed, and a number of those guards have been used. However, many of those guards for air-moving devices fail to give sufiicient protection against contact with the rotating portions of the air-moving devices, while other of those guards unduly restrict the flow of air to the rotating portions of those air-moving devices. Still other of those guards for air-moving devices are unduly expensive to manufacture and to mount. For these various reasons prior guards for air-moving devices are objectionable. The present invention obviates these objections by providing a guard which includes a number of turns of wide fiat strip. Such a guard can have sizable spacing between the adjacent turns of the strip while giving fullprotection against contact with the rotating portions of the air-moving device, because such a guard will exclude everything except elongated, axially-aligned objects of small, uniform cross-section. Such a guard will have ample strength, and yet it will present minimum resistance to the flow of air to the air-moving device. 'It is therefore an object of the present invention to provide a guard for air-moving devices which includes a number of turns of wide flat strip. 7

The turns of the wide fiat strip of the guard provided by the present invention act to channel the air into the air-moving device, and thus they tend to eliminate the eddying of air commonly noted-adjacent the intake areas of air-moving devices. In addition, the turns of the flat wide strip will resist the tendency of the air, entering the air-moving device, to move angularly of includes a continuous, wide, flat strip which is 4 Claims. (Cl. 230275) wound in the form of a spiral. The wide, flat strip is made of a springy metal and it will be dimensioned so it will, when removed from the mandrel on which it is wound, automatically assume the desired spiral. Such a wide, flat strip is exceedingly economical to manufacture and to mount, because it does not require precise interfitting of a number of individual parts; that strip being a single unit. It is therefore an object of the present invention to provide a guard which has a continuous, wide, fiat strip of sprin y metal and which can be Wound on a mandrel so it will, when released, assume the desired spiral.

The guard provided by the present invention includes the continuous, wide, flat strip in the form of a spiral and a number of radially-directed supporting bars. These bars not only support the continuous, wide, flat strip but they also support the driving motor of the air-moving device. In this way, the guard obviates any need for a separate mounting for the driving motor of the air-moving device. In doing this, the guard provided by the present invention offers minimum resistance to the flow of air to the air-moving device. It is therefore an object of the present invention to mount the driving motor and the continuous wide, flat strip of an air-moving device on radially-directed bars.

Other and further objects and advantages of v the present invention should become apparent from an examination of the drawing and accompanying description.

In the drawing and accompanying description window fan and that embodies the principles and teachings of the present invention, and

Fig. 2 is a sectional view of a part of the airmoving device and window fan shown in Fig. 1.

Referring to the drawing in detail, the numeral l0 denotes the frame of a window fan. The frame [0 has a Venturi ring l2 located at the approximate center thereof, and that ring will pass air while the rest of the frame Ill acts as a baflie. A number of radially-directed bars 14 are secured to the frame 10 adjacent the Venturi ring I2 by rivets IE or other fastening devices; and the radially-directed bars [4 extend inwardly toward the housing 20 of the driving motor of theair-moving device. The inner ends of the radially-directed bars i l have openings therethrough, and those openings receive rivets IE! or other fastening devices. The rivets l9 also extend through openings in brackets I! that project outwardly from the motor housing 20; the brackets I'l beingsolidly secured to the motor for the air-moving device. :In this way, the fastening devices [6 and l 9 coact with frame l0, brackets I! and bars l4 to hold the motor of the airmoving device fixed relative to the frame it). The radially-directed bars M are bent to have a' V- shaped cross section. Such a cross-section strengthens those bars while. reducingthe overall width of those bars; thus reducingitheir 're-.- sistance to the passage of air.

A continuous, flat, wide strip! is supported by the radially-directed bars II; and that strip forms a spiral which extends from the inner ends of the bars [4 to the outer ends of those bars. The various turns of the spiral are all spaced apart equal distances. The spiral formed from the strip l8 has a conical configuration; each turn of the spiral extending rearwardly of the. nextoutermost turn of said spiral. The spiral formed from strip 18 overlies the annular spacebetween the motor housing 26 and the Venturi ring 12 of the frame I; and in doing so it-protects the hands, fingers and other portions of the anatomies of persons, as by keeping them from contacting the rotating portion of the air-moving device. That rotating portion carries a number of blades 22 which will cause air to move through the Venturiring i2 when the motor isoperating.

The continuous strip 18 is secured to the rear surfaces of the bars l4; and it is preferably secured to each of those bars by welding. In forming the continuous strip l8, a flat, wide strip of springy metal of the proper length is selected, and it is wound on a mandrel of such size that, when released, the strip 18 will automaticall assume the'desired spiral. The formation of the spiral in this way makes it unnecessary-to interfit a number of parts and then secure them to a support; it only being necessary to weld the radiallydirected bars Hto the various turns of the strip I8. In assembling the strip 18' with the bars id, it has been found quite simpleand'quite desirable to use a grooved aligning fixture for the strip 18 which has the correct conical configuration, has the requiredprecise spacing between adjacent turns of the spiral, and hasguides for the bars [4. Withsuoh a fixture itisexceedingly easy to place the preformed spiral on the fixture,

press the turns of the spiral into the grooves of the fixture, place the bars I 45in the guides therefor; and, spot weld the barstothe-spiral-x By attaching the aligning fixture to -the spot weldingdevice, the entire operation canrb'e made semiautomatic. The saving in time and cost through use of such a guard is considerable; amounting,-

to a saving on eachguard 'of'thirty cents ($.30) in labor cost alone.

The radially-directed bars I 4-not onlysupport the continuous strip l8 but they also support the motor housing 28-. This is very, desirable be cause it eliminates all needfor aseparate support for the motor and" thus minimizes the num-- her and area of obstructionstothe fiowof-air to v the air-moving device.

In one preferred form' of strip i8 is madefrcm a'flat strip of: metal that is one half /2) of an inch. wide-'and is fiveone hundredths (0.05) ofan inch thick; and each ofthe turns of the spiral formed by that strip isspacedthe invention, the

one half /2) of an inch from the turns adjacent to it. Each turn of the spiral will extend approximately two tenths (02) of an inch rearwardly of the turn disposed outwardly of it. The use of a strip with a width that equals the spacing between the turns of the spiral is very desirable because it makes possible theuse of a large spacing between the turns of the spiral without increasing the risk to the fingers, hands, or other portions of the anatomies of individuals. The flat, wide strip does this by preventing the passageof objects-to the air-moving device except when'the" objects are directly aligned with the axis of the air-moving device, when those ob- .jects'arev of small, uniform cross sections, and when those objectsare long enough to extend through the guard and extend to the rotating portion of the air-moving device. The wide spacing between adjacent turns of the guard reduces the area occupied by the material of the guard and thus minimizes the guards resistance to the fiowof air. The conical configuration of the guard is desirable because it prevents straightline, radial movement of air or physical objects.

through the guard.

The turns of the strip iii are all aligned with these things, the guard providedby the present invention increases theefiiciency of operationof the air-moving device.

The fram It of the air-moving. device is-provided with extensiblewings 24-. that can be telescoped outwardly from that frame to fit Wide window frames. Those-wings can. of course, be retracted until they are adjacent the frame lfl so they can fit theframesof narrow windows. Wing nuts 26 coactwith bolts extending through openings in the wings 24 and-frame I0 to holdv the wings 24 against undesired movement.

Whereas a preferred embodiment of the present invention has been shown and'described in the drawing and accompanying description it should be apparent to those skilled in the art that various changesmay be made in the. form of the invention without aifecting the scope thereof;

What I claim is:

l. A guard that is adapted tov be used adjacent an air-movingdevicethat has .a driving motor.

and a supporting frame and: that comprises a continuous flat, wide strip of metal wound in aspiral, a frame to support said driving motor, said motor-supporting frame being at the center.

of said spiral and being the inner 'terminusofl ing a number of widelyspaced turns that have their wide faces-directed axially of said spiralv 2. A guard that isadapted to be used adjacent an air-moving device that has a driving motorand a supporting frame and that comprisesa continuous flat, wide. strip of metal woundin a 1 spiraL'a frame to support said driving motor,-

said motor-supporting frame being at the centeri of said spiral and being the inner terminus of said spiral, said motobsupporting frame being a ring, and a plurality of radially-extending bars supporting said strip and said motor-supporting frame, each of said radially-extending bars extending from the motor-supporting frame of said air-moving device to the supporting frame of said air-moving device and being secured to and supporting every turn of said spiral, said strip having a number of widely spaced turns that have their wide faces directed axially of said. spiral, the spacing between adjacent turns of said strip being approximately equal to the width of said strip.

3. A guard that is adapted to be used adjacent an air-moving device that has a driving motor and a supporting frame and that comprises a continuous fiat, wide strip of metal wound in a spiral,-'

a frame to support said driving motor, said motor:

supporting frame being at the center of said I of said strip forming a cone extending between said frame and said motor.

4. A guard that is adapted to be used adjacent an air-moving device that has a driving motor and a supporting frame and that comprises a continuous flat, wide strip of metal wound in a spiral, and a plurality of radially-extending bars supporting said strip, said radially-extending bars extending from the driving motor of said air-moving device to the supporting frame of said air-moving device, said strip having a number of widely spaced turns that have their wide faces directed axially of the motor of said airmoving device, said guard being conical in configuration, each of the turns of said strip having the trailing edge thereof spaced slightly rearwardly of the trailing edge of the next-outermost turn of the strip but having its leading edge spaced forwardly of the trailing edge of said next-outermost turn of the strip, said rearward disposition of said turns being such that the turns of said strip prevent a straight-line radial path through said guard at right angles to the axis of said spiral. I

CARL M. BUTTNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain May 26, 1938 

